Many building structures incorporate expansion joints to accommodate the movement of structural elements as a result of temperature changes or seismic activity. In order to prevent moisture from entering the expansion joints, it is necessary to protect the joints with a waterproof cover. Typical expansion joint covers comprise an elongated bellows the side edges of which are connected to metal mounting flanges. The flanges are attached to support members of the building structure which are spaced from each other on either side of the expansion joint, so that when the support members move relative to each other the bellows will be able to yield or flex with the movement. Because the bellows remains attached to the support members during such movement, the expansion joint cover continues to protect the expansion joint against the entry of moisture.
In addition to waterproofing expansion joints, many architectural and engineering structural designs require the joint to be insulated. For the insulation to be effective for any length of time it is also necessary to provide a vapor barrier to prevent moisture in the form of condensate from the interior environment of the building from entering the insulation. Therefore, it is common practice when installing an expansion joint cover under these conditions to first drape a vapor barrier into the joint opening and to then stuff the joint opening above the vapor barrier with insulation. Then the preformed expansion joint cover is attached to the structural elements on either side of the joint opening.
Not only is this procedure time consuming, and therefore not economically desirable, it is also difficult to maintain high standards of quality control. As long as the installation procedure requires the joint cover to be fabricated in the field, these problems will continue to exist. Until the present invention, there had been no satisfactory way of overcoming the drawbacks of this conventional practice.